On my headunit (pioneer premiere DEH680MP) it tells me the volts of my battery and it stays pretty consistant around 12.5v at 1000-2500 rpm when the system is at about volume 45 of 62. When I stomp on the gas real quick (in neutral) it will shoot up to 14v but only at very high rmps. I have a 170 amp HO alt from nate and the big 3 with 0 gauge. The system is only drawing 1000wrms all together. I have a battery that is a few years old and its not a very good one at about 500cca. Is there anything I should get or do to improve this? New battery? Cap?
If you want to measure voltage hook a DMM up to your battery and check there. Measuring at the radio is essentially pointless as the gauge of wire, ground points and fusing all conspire to drop voltage before it hits the radio (although Pioneer DOES tell you to run your power to the battery and ground the unit to clean "shiny" metal; in which case the reading may get slightly more accurate)